It is customary to add admixtures to hydraulic compositions, in order to modulate the properties thereof during application and after hardening.
It is thus known how to modify the hydraulic setting characteristics by adding set-accelerating agents and set-retardants.
Accelerating the setting is particularly of interest economically since it allows an increase in the manufacturing rate and also allows working under winter conditions.
Certain salts, notably alkaline salts like sodium chloride or earth alkaline salts like calcium chloride are widely used as accelerators for setting and hardening Portland cement.
The capability of these salts of improving mechanical strengths in compression may however be limited in the case of cements with low clinker content, because these salts accelerate more particularly the hydration of the phases of the clinker.
In order to limit corrosion caused by an excessive content of chlorides, patent U.S. Pat. No. 4,318,744 proposes admixtures including an alkanolamine.
However, the formulation of an admixture comprising several compounds associated with the various admixtures may pose problems. Thus, formulations of admixtures that associate sulfates and alkaline salts are not stable at low temperature, since they tend to crystallize when stored under cold conditions, because of low solubility of sodium sulfate. In order to avoid precipitation of the alkaline sulfate of the solution, it is then necessary to store these admixtures in a heated environment.